Spontaneous symmetry breaking in a two-doublet lattice Higgs model

An SU(2) lattice gauge theory with two doublets of complex scalar fields is considered. All continuous symmetries are identified and, using the nonperturbative methods of lattice field theory, the phase diagram is mapped out by direct numerical simulation. Two-doublet models contain phase transitions that separate qualitatively distinct regions of the parameter space. In some regions global symmetries are spontaneously broken. For some special choices of the model parameters, the symmetry-breaking order parameter is calculated. The pattern of symmetry breaking is verified further through observation of Goldstone bosons.Comment: 24 pages, 13 figures, references added, published versio

Nash Codes for Noisy Channels

This paper studies the stability of communication protocols that deal with transmission errors. We consider a coordination game between an informed sender and an uninformed decision maker, the receiver, who communicate over a noisy channel. The sender's strategy, called a code, maps states of nature to signals. The receiver's best response is to decode the received channel output as the state with highest expected receiver payoff. Given this decoding, an equilibrium or "Nash code" results if the sender encodes every state as prescribed. We show two theorems that give sufficient conditions for Nash codes. First, a receiver-optimal code defines a Nash code. A second, more surprising observation holds for communication over a binary channel which is used independently a number of times, a basic model of information transmission: Under a minimal "monotonicity" requirement for breaking ties when decoding, which holds generically, EVERY code is a Nash code.Comment: More general main Theorem 6.5 with better proof. New examples and introductio

Far-Ultraviolet Dust Albedo Measurements in the Upper Scorpius Cloud Using the SPINR Sounding Rocket Experiment

The Spectrograph for Photometric Imaging with Numeric Reconstruction (SPINR) sounding rocket experiment was launched on 2000 August 4 to record far-ultraviolet (912-1450 A) spectral and spatial information for the giant reflection nebula in the Upper Scorpius region. The data were divided into three arbitrary bandpasses (912-1029 A, 1030-1200 A, and 1235-1450 A) for which stellar and nebular flux levels were derived. These flux measurements were used to constrain a radiative transfer model and to determine the dust albedo for the Upper Scorpius region. The resulting albedos were 0.28+/-0.07 for the 912-1029 A bandpass, 0.33+/-0.07 for the 1030-1200 A bandpass, and 0.77+/-0.13 for the 1235-1450 A bandpass

Robust, data-driven inference in non-linear cosmostatistics

We discuss two projects in non-linear cosmostatistics applicable to very large surveys of galaxies. The first is a Bayesian reconstruction of galaxy redshifts and their number density distribution from approximate, photometric redshift data. The second focuses on cosmic voids and uses them to construct cosmic spheres that allow reconstructing the expansion history of the Universe using the Alcock-Paczynski test. In both cases we find that non-linearities enable the methods or enhance the results: non-linear gravitational evolution creates voids and our photo-z reconstruction works best in the highest density (and hence most non-linear) portions of our simulations.Comment: 14 pages, 10 figures. Talk given at "Statistical Challenges in Modern Astronomy V," held at Penn Stat

Discovery of three z>6.5 quasars in the VISTA Kilo-degree Infrared Galaxy (VIKING) survey

Studying quasars at the highest redshifts can constrain models of galaxy and black hole formation, and it also probes the intergalactic medium in the early universe. Optical surveys have to date discovered more than 60 quasars up to z~6.4, a limit set by the use of the z-band and CCD detectors. Only one z>6.4 quasar has been discovered, namely the z=7.08 quasar ULAS J1120+0641, using near-infrared imaging. Here we report the discovery of three new z>6.4 quasars in 332 square degrees of the Visible and Infrared Survey Telescope for Astronomy Kilo-degree Infrared Galaxy (VIKING) survey, thus extending the number from 1 to 4. The newly discovered quasars have redshifts of z=6.60, 6.75, and 6.89. The absolute magnitudes are between -26.0 and -25.5, 0.6-1.1 mag fainter than ULAS J1120+0641. Near-infrared spectroscopy revealed the MgII emission line in all three objects. The quasars are powered by black holes with masses of ~(1-2)x10^9 M_sun. In our probed redshift range of 6.44<z<7.44 we can set a lower limit on the space density of supermassive black holes of \rho(M_BH>10^9 M_sun) > 1.1x10^(-9) Mpc^(-3). The discovery of three quasars in our survey area is consistent with the z=6 quasar luminosity function when extrapolated to z~7. We do not find evidence for a steeper decline in the space density of quasars with increasing redshift from z=6 to z=7.Comment: 14 pages, 9 figures. Published in Ap

So you call that research? : mending methodological biases in strategy and organization departments of top business schools

We believe that all strategy and organization (SO) scholars should be able to decide for themselves whether to specialize in certain parts of the knowledge cycle or adopt a broader, multi-method view on the scientific process. In a situation of ―methodological pluralism‖, individuals might choose to contribute to the construction of new administrative theories by means of qualitative works like case studies, ethnographies, biographies, or grounded theory studies (e.g., see Denzin and Lincoln, 2000). Others could then specialize in testing these theories by means of experiments, surveys, or longitudinal econometric studies (e.g., see Lewis-Beck, 1987-2004). Again others could combine both approaches in Herculean attempts to conduct high-impact, integrative research with the potential to change the way we understand the field as a whole

Multilingual assessment of early child development: Analyses from repeated observations of children in Kenya.

In many low- and middle-income countries, young children learn a mother tongue or indigenous language at home before entering the formal education system where they will need to understand and speak a countrys official language(s). Thus, assessments of children before school age, conducted in a nations official language, may not fully reflect a childs development, underscoring the importance of test translation and adaptation. To examine differences in vocabulary development by language of assessment, we adapted and validated instruments to measure developmental outcomes, including expressive and receptive vocabulary. We assessed 505 2-to-6-year-old children in rural communities in Western Kenya with comparable vocabulary tests in three languages: Luo (the local language or mother tongue), Swahili, and English (official languages) at two time points, 5-6&nbsp;weeks apart, between September 2015 and October 2016. Younger children responded to the expressive vocabulary measure exclusively in Luo (44%-59% of 2-to-4-year-olds) much more frequently than did older children (20%-21% of 5-to-6-year-olds). Baseline receptive vocabulary scores in Luo (β&nbsp;=&nbsp;0.26, SE&nbsp;=&nbsp;0.05, p&nbsp;&lt;&nbsp;0.001) and Swahili (β&nbsp;=&nbsp;0.10, SE&nbsp;=&nbsp;0.05, p&nbsp;=&nbsp;0.032) were strongly associated with receptive vocabulary in English at follow-up, even after controlling for English vocabulary at baseline. Parental Luo literacy at baseline (β&nbsp;=&nbsp;0.11, SE&nbsp;=&nbsp;0.05, p&nbsp;=&nbsp;0.045) was associated with child English vocabulary at follow-up, while parental English literacy at baseline was not. Our findings suggest that multilingual testing is essential to understanding the developmental environment and cognitive growth of multilingual children

Squeezed States of the Generalized Minimum Uncertainty State for the Caldirola-Kanai Hamiltonian

We show that the ground state of the well-known pseudo-stationary states for the Caldirola-Kanai Hamiltonian is a generalized minimum uncertainty state, which has the minimum allowed uncertainty $\Delta q \Delta p = \hbar \sigma_0/2$, where $\sigma_0 (\geq 1)$ is a constant depending on the damping factor and natural frequency. The most general symmetric Gaussian states are obtained as the one-parameter squeezed states of the pseudo-stationary ground state. It is further shown that the coherent states of the pseudo-stationary ground state constitute another class of the generalized minimum uncertainty states.Comment: RevTex4, 9 pages, no fingure; to be published in Journal of Physics

On the miscibility of cardiolipin with 1,2-diacyl phosphoglycerides: Binary mixtures of dimyristoylphosphatidylethanolamine and tetramyristoylcardiolipin

The thermotropic phase behavior and organization of model membranes composed of binary mixtures of the quadruple-chained, anionic phospholipid tetramyristoylcardiolipin (TMCL) with the double-chained zwitterionic phospholipid dimyristoylphosphatidylethanolamine (DMPE) were examined by a combination of differential scanning calorimetry (DSC) and Fourier-transform infrared (FTIR) spectroscopy. After equilibration at low temperature, DSC thermograms exhibited by binary mixtures of TMCL and DMPE containing < 80 mol DMPE exhibit a fairly energetic lower temperature endotherm and a highly energetic higher temperature endotherm. As the relative amount of TMCL in the mixture decreases, the temperature, enthalpy and cooperativity of the lower temperature endotherm also decreases and is not calorimetrically detectable when the TMCL content falls below 20 mol%. In contrast, the temperature of the higher temperature endotherm increases as the proportion of TMCL decreases, but the enthalpy and cooperativity both decrease and the transition endotherms become multimodal. The FTIR spectroscopic results indicate that the lower temperature endotherm corresponds to a lamellar crystalline (Lc) to lamellar gel (Lβ) phase transition and that the higher temperature transition involves the conversion of the Lβ phase to the lamellar liquid-crystalline (Lα) phase. Moreover, the FTIR spectroscopic signatures observed at temperatures below the onset of the Lc/Lβ phase transitions are consistent with the coexistence of structures akin to a TMCL-like Lc phase and the L β phase, and with the relative amount of the TMCL-like L c phase increasing progressively as the TMCL content of the mixture increases. These latter observations suggest that the TMCL and DMPE components of these mixtures are poorly miscible at temperatures below the L β/Lα phase transition temperature. Poor miscibility of these two components is also suggested by the complexity of the DSC thermograms observed at the Lβ/Lα phase transitions of these mixtures and with the complex relationship between their Lβ/Lα phase transition temperatures and the composition of the mixture. Overall, our data suggests that TMCL and DMPE may be intrinsically poorly miscible across a broad composition range, notwithstanding the homogeneity of the fatty acid chains of the two components and the modest (~ 10 °C) difference between their Lβ/Lα phase transition temperatures.Fil: Frías, María de los Ángeles. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Benesch, Matthew G. K.. University of Alberta; CanadáFil: Lewis, Ruthven N. A. H.. University of Alberta; CanadáFil: McElhaney, Ronald N.. University of Alberta; Canad